Current NIGMS-SBIR funding supported InvivoSciences LLC's (IVS) launch of several product lines in 2010. IVS generated revenues from the sales of three-dimensional (3D) cell culture tools (MC-8TM and IVS InsertsTM) that can grow various hydrogel tissues without any support layers. The culture tools enable Palpator TM and Tissue StretcherTM to stretch the hydrogel tissues for biomechanical measurements and mechanical conditioning (e.g., cyclic stress applications), respectively. IVS also performed contract research services, using our tools and devices, for industry and academic laboratories for profiling compound-induced effects on cell and tissue physiology. To further demonstrate our ability to screen drug candidates, especially for drug developers, the market demands benchmark studies against compounds and drugs whose pharmacological functions, including toxicity information, have been well-characterized. To fully commercialize our current start- up activities, IVS will improve its rapid drug screening system that uses engineered heart tissues (EHTs) to monitor the effects of test compounds on cardiac contractility and associated regulatory molecules. In Aim 1, EHTs will be developed using cardiomyocytes derived from human induced pluripotent stem (iPS) cells to commercialize a drug screening system using human samples. Using this system, we will determine the beneficial and toxic effects of a panel of drugs, based on the drug-induced changes in the cardiac functions of EHTs, as well as the signal transduction pathways that underlie their activities. In Aim 2, we will establish ISO 13485:2003-specified requirements for a quality management system so that we may more confidently provide contract research services for drug developers. In addition, using a list of 16 well-known cardio effective and toxic drugs/compounds, we will measure drug-induced cardiac function changes using EHTs to establish the benchmark. In Aim 3, we will identify mechanisms of cardiotoxicity, and will demonstrate the ability of the EHTs to predict cardiotoxicity in vitro, without the need for establishing animal studies. Our approach will advance drug target identification and optimization as well as biomarker discovery-critical for diagnosing cardiotoxicity. As a demonstration of the ability of our approach to elucidate a mechanism of cardiotoxicity, we will use, as an example, genetic knockdown with shRNA and drugs to inhibit mTOR (mammalian target of rapamycin). Successful completion of our aims will prove the ability of our in vitro system to predict drug-induced cardiotoxicity in humans, clearly benefiting early-stage drug discovery.